The invention relates to the preparation of a topical medication for very quick alleviation and relief of itching and/or localized pain caused by a wide range of medical indications.
Itching (pruritus) has a lot of underlying causes and can lead to a lot of complications by scratching. Itching may be associated with local pain. Pain can also occur independently. Both local pain and itching comprise the sensation associated with a lot of causes: inflammation, dry skin, infection by micro-organisms such as bacteria, fungi and viruses, corns, wounds, ulcers, stings, insect bites, allergic reactions, hyper proliferation of the epithelial layer, different types of treatment with chemicals, affecting the skin, eczema, etc. But there is also local pain associated with other affections, such as tendinitis, rheumatism and rheumatic affections, such as reumatalgia, reumatide reumatismus articulorum acutus, reumatismus articulorum chronicus, reumatismus musculorum, reumatismus nervosum, reumatismus nodosum, rheumatoid affections, different kinds of arthritis such as arthritis urica, arthritis acuta, arthritis sicca, arthritis hyperthrophica, arthritis infectiosa, arthritis rheumatica, different forms of arthrosis, skin burning by sun, other irradiations, chemicals or heat sources.
In all these and other cases pain and/or itching may very often be difficult to treat. Moreover, oral pain killers may have undesired side effects due to their systemic mode of action, especially when taken over a prolonged period of time. Itching in itself can be very inconvenient and scratching can deteriorate the condition.
It is therefore desirable and thus the object of the invention to provide a means for topically treating itching and local pain.
This object was achieved according to the invention when it was found that glucosamine and derivatives thereof when applied topically are capable of controlling, reducing and also inhibiting the initiation of itching and pain caused by a whole range of unrelated conditions.
The medicinal capacity of glucosamine after oral ingestion thereof in a limited number of diseases has been described in the literature. A pilot study of the oral use of N-acetyl-D-glucosamine as a potential treatment for patients with osteoarthritis was published by Talent and Gracy (1996). The potential use of oral glucosamine for wound healing and treatment for osteoarthritis is discussed by McCarty (1994 and 1996). The use of glucosamine in non-specific inflammatory bowel diseases is documented by Aasakura et al. (1995). Reichelt et al. (1994) demonstrated the efficacy and safety of intramuscular glucosamine sulfate in osteoarthritis of the knee.
The use of glucosamine as non steroidal anti-inflammatory drug in reducing the signs and symptoms of osteoarthritis and rheumatoid arthritis is documented by Spencer-Green (1993) and Setnikar (1992). The toxicity of glucosamine for tissue culture cells and the antiviral activity of glucosamine depending on the cell-type and cell-line were demonstrated by Schmidt et al. (1989) and Delgadillo and Vanden Berghe (1988).
More complicated glucosamine compounds were evaluated for use in patients with osteoarthritis of the knee. In the study by Dragani et al. (1989, 1990) heparin-glucoronil glucosaminoglycan was used in a long-term study for 30 days in a 3 daily administration of the drug.
All of these prior art documents are however concerned with oral intake of glucosamine or a derivative thereof. Based on this systemic mode of action it could not be expected that topical application of the compound and/or its derivative(s) could have an alleviating effect on itching and pain.
The present invention provides for the use of glucosamine and/or its derivatives for the preparation of a therapeutical composition for the topical treatment of itching and/or pain. The effect of the mediation is an acupuncture-like effect, i.e. resulting in a very quick pain reduction.
The invention thus provides topical medicaments for the alleviation of itching and pain. It has surprisingly been found that this alleviation can already take place in a very short delay of time ( less than 1 minute) by single topical treatment. The use of glucosamine or glucosamine derivatives for the topical treatment of indications involving pain and/or itching were never described before. It is also totally new and unexpected that water-soluble compounds, such as glucosamine or glucosamine derivatives, are at all able to penetrate the skin or mucosa and act so quickly on neurons and nerve impulses causing the sensation of irritation and pain. The effect is therefore called: an acupuncture-like effect.
The use according to the present invention requires glucosamine and/or one or more monomeric glucosamine derivatives such as:
D-glucosamine hydrochloride
D-glucosamine sulfate
D-glucosamine iodide or other salts of D-glucosamine
N-acetyl D-glucosamine and their salts
Chitin hydrolysate
Chitosane hydrolysate
Glucosamine phosphates, sulfates, or acetates and their salts
D-glucosaminic acid
N-acetyl D-glucosamine phosphates, sulfates and their salts
Hydrolysates of chitin and chitosane can be obtained by chitinase.
The compounds mentioned here are preferably comprised in the therapeutical compositions (also referred to herein as xe2x80x9ctopical medicamentxe2x80x9d) of the invention in a concentration from 0.1% to 15% (w/w), most preferably from 1% to 10% (w/w).
Topical medicaments prepared according to the invention may further comprise other active compounds for healing diseases that are accompanied by local itching or pain, such as disinfectants, antibiotics, antifungal compounds, wound healing compounds, cosmetic compounds improving the skin conditions, anti-inflammatory compounds, anti-allergic compounds, anti-rheumatic compounds, anti-arthritic compounds, other pain or itching relieving compounds, etc.
According to the invention it has been found that the itching or local pain is completely removed or significantly reduced in a short delay of time of even less than 1 minute for a significant period of at least more than 1 hour considered that appropriate concentrations of the drug are used. Appropriate concentrations comprise more than about 0.1% (w/w) glucosamine compound per gram cream, gel, ointment, solution, etc..
All topical medicaments, prepared according to the invention, may be prepared in any conventional form or in other forms suitable for topical use on the skin or mucous membranes. These forms also include all forms with sustained release compositions or pre-dispersed plasters and other forms containing an acceptable carrier for the compounds.
Cosmetic acceptable carriers and additives may include: forms of vaseline, oils, emollients, surfactants, humefactants, powders, water, preservatives, agents increasing the viscosity such as polysaccharides, polypeptides, fragrances, anti-foam agents, opacifiers, colorants, each in their amount to accomplish their typical function. The basic compositions of the various topical application forms described here are well within the reach of the skilled person.